Javascript gravity simulator!

This is a DHTML gravity simulator I threw together in Javascript as an
exercise. Hence the name "javascript gravity simulator". To add new planets
click and drag, the further you drag the faster they will go. To clear all the
planets press 'c'.

There are better gravity simulators out there, notably ones that use the canvas
element instead of moving around text, but this was fun to build.

Finally, I've only tested this in Firefox,
Chrome, and Safari. As
such I have no guarantees about its behaviour in other browsers. Luckily if you
desperately need to see planets in javascript, Firefox is free!